Photogrammetry

With a focus on providing a full range of surveying, mapping, and remote sensing services, Merrick & Company provides the following specific services for clients’ needs.

  • Digital orthophotography
  • Digital photogrammetric mapping
  • Aerial photography

Digital Orthophotography
Merrick has delivered customized digital orthophotography images to clients since 1990, including providing services to:

  • Australian American Energy Company
  • State of Chihuahua, Mexico
  • Colombian Navy
  • ConocoPhillips
  • Cook County, Illinois
  • City of Juarez, Mexico
  • Southwest Florida Water Management District
  • U.S. Air Force
  • U.S. Department of Agriculture
  • U.S. Department of Defense
  • U.S. Department of Energy
  • Xcel Energy

The firm’s system is completely integrated into its photogrammetric mapping and GIS processes and, during the project, Merrick’s team uses the LH Systems SOCET SET software and the Zeiss SCAI scanner to rigorously calculate and generate precision ortho data from the original scanned negatives. To accommodate client needs, Merrick has the capabilities of providing digital ortho photos in a variety of media and formats including TIFF, BIL, and BIP.

Accuracy is the top priority, thus, Merrick puts considerable attention to managing ground/camera/photo relationships in order to precisely model and modify digital image geometries. In addition, image distortions are corrected for camera tip/tilt, terrain relief displacement, film deformation, lens aberrations, earth curvature, and atmospheric refraction and final quality is managed by crosschecking for any image flaws, checking tile edges, and fitting the mapping for on-screen specifications.

Digital Photogrammetric Mapping
Merrick, a national leader in digital photogrammetric mapping, change detection and GIS database updating, tailors its data collection to clients’ exact requirements and GIS format. Through the resources of an experienced team and the use of the latest in softcopy photogrammetry technology, including ArcGIS and PC-based applications, Merrick accurately and cost-effectively collects, edits, and translates digital planimetric and topographic data to meet specific client needs.

To achieve completeness and accuracy of each map product, the company uses specific quality control measures that incorporate the use of verification software, operator verification, check plots, and independent editing. This includes adhering to and/or exceeding the standards of:

  • National Map Accuracy Standards (NMAS)
  • American Society of Photogrammetry and Remote Sensing (ASPRS)
  • National Standard for Spatial Data Accuracy (NSSDA)

Aerial Photography
To meet clients’ specific aerial photography needs, the Merrick team, highly experienced in mission and flight planning, provides digital imagery acquisition using a Digital Airborne Camera System (DACS™). To provide supporting aerial photography, Merrick engages selected subcontractors. Through these resources, Merrick has the capabilities of acquiring vertical mapping, airborne global positioning system (AGPS), and oblique landscape photography in black and white, color, and/or color infrared film formats. In acquiring this detailed photography, Merrick:

  • Coordinates with clients on needs, map sheet layout, model layout, flight plan, and camera calibration to ensure the project plan meets client goals
  • Inspects the acquired photography to validate its conformation to client and Merrick specifications
  • Ensures the photography conforms to industry standards for weather conditions, processing, camera calibration, film type, side lap, forward lap, tip, tilt, crab, cloud coverage, and sun angle
  • Typically provides an Aerial Photography Quality and Acceptance Report that documents the parameters to which the photography was flown